INFO: task syz-executor235:4161 blocked for more than 143 seconds. Not tainted 5.15.179-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor235 state:D stack:25176 pid: 4161 ppid: 4159 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375 schedule+0x11b/0x1f0 kernel/sched/core.c:6458 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191 __writeback_inodes_sb_nr+0x2ce/0x370 fs/fs-writeback.c:2684 sync_filesystem+0xa0/0x220 fs/sync.c:54 generic_shutdown_super+0x6b/0x310 fs/super.c:448 kill_block_super+0x7a/0xe0 fs/super.c:1427 kill_f2fs_super+0x2ff/0x3c0 fs/f2fs/super.c:4538 deactivate_locked_super+0xa0/0x110 fs/super.c:335 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143 task_work_run+0x129/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f4947b804c7 RSP: 002b:00007fff681a2578 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f4947b804c7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff681a2630 RBP: 00007fff681a2630 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000206 R12: 00007fff681a36a0 R13: 00005555790b56c0 R14: 431bde82d7b634db R15: 00007fff681a36c0 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8cb1f4e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 5 locks held by kworker/u4:4/1439: 2 locks held by getty/3929: #0: ffff88807ec19098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cd62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 1 lock held by syz-executor235/4161: #0: ffff8880290620e0 (&type->s_umount_key#43){+.+.}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.179-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:369 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 1439 Comm: kworker/u4:4 Not tainted 5.15.179-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:should_resched arch/x86/include/asm/preempt.h:-1 [inline] RIP: 0010:unwind_next_frame+0x143e/0x1fa0 arch/x86/kernel/unwind_orc.c:616 Code: 0f 85 78 02 00 00 c6 05 82 36 be 0c 01 48 c7 c7 e0 94 a8 8a e9 0e fa ff ff bf 01 00 00 00 e8 29 d2 1e 00 65 8b 0d 9a a2 c9 7e 01 85 c9 0f 85 a1 02 00 00 e8 63 bf c7 ff e9 97 02 00 00 80 3d RSP: 0018:ffffc90005606248 EFLAGS: 00000297 RAX: 0000000080000001 RBX: ffffc90005606310 RCX: 0000000080000000 RDX: dffffc0000000000 RSI: ffffc900056079b0 RDI: 0000000000000001 RBP: ffffc900056079c0 R08: ffffc900056079b0 R09: ffffc90005606350 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1d1cefe R13: 1ffffffff1d1cefe R14: ffffc90005600000 R15: ffffc90005606300 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe07b76d7c CR3: 000000002aff1000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 mempool_alloc+0x17f/0x590 mm/mempool.c:393 bio_alloc_bioset+0x132/0x8c0 block/bio.c:466 f2fs_grab_read_bio+0x9f/0x720 fs/f2fs/data.c:990 f2fs_submit_page_read+0xb8/0x2c0 fs/f2fs/data.c:1035 f2fs_get_read_data_page+0x455/0x6b0 fs/f2fs/data.c:1224 f2fs_get_lock_data_page+0x54/0x250 fs/f2fs/data.c:1271 move_data_page fs/f2fs/gc.c:1336 [inline] gc_data_segment fs/f2fs/gc.c:1547 [inline] do_garbage_collect+0x3645/0x7540 fs/f2fs/gc.c:1671 f2fs_gc+0x9d2/0x1c30 fs/f2fs/gc.c:1765 f2fs_balance_fs+0x4e8/0x6a0 fs/f2fs/segment.c:529 f2fs_write_inode+0x4be/0x660 fs/f2fs/inode.c:738 write_inode fs/fs-writeback.c:1495 [inline] __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1705 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930 wb_writeback+0x451/0xc50 fs/fs-writeback.c:2104 wb_do_writeback fs/fs-writeback.c:2247 [inline] wb_workfn+0x46c/0x1130 fs/fs-writeback.c:2288 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.327 msecs